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RF detector

Discussion in 'Radio and Wireless' started by Jeanguypataterubberboot, Sep 7, 2018.

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  1. Jeanguypataterubberboot

    Jeanguypataterubberboot

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    Jul 9, 2013
    I have an idea for a project and I would like some input on if it can be done and how. I am looking to build a device that I can place close to my HF ham radio and when I key the mic and speak will detect the RF and light an "ON THE AIR" sign. I was thinking of using transistors to amplify the signal and then turn on a lighted sign.

    Does this make sense?
    Thanks for the input.

    Pierre
     
  2. hevans1944

    hevans1944 Hop - AC8NS

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    You have an amateur radio license and still need to ask this question? What is your call sign and class of license?
     
  3. Jeanguypataterubberboot

    Jeanguypataterubberboot

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    So you have no relevant input to offer?
     
  4. kellys_eye

    kellys_eye

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    I echo @hevans1944 concerns. Anyone holding a decent amateur classification license would have the requisite technical knowledge to fully understand the needs and solutions for the OP's proposal - it's 'baby stuff' as far as genuine amateur radio operators are concerned.

    But there are people who use amateur equipment WITHOUT the proper qualifications and true amateur radio operators frown upon this practice as it demeans the hobby.

    Why are you avoiding the issue?
     
  5. Jeanguypataterubberboot

    Jeanguypataterubberboot

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    I'm not avoiding anything. I have a project that I was asking for input on and all I am getting is stupid responses from people who obviously don't know anything about the subject. I do hold a ham radio license and understand the subject matter very well. I was simply trying to see if anyone had done this before and how the went about it.

    If you can't say anything useful then I suggest you shut up or better yet, turn your computer off.
     
  6. WHONOES

    WHONOES

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    Why don't you fit a mic key switch that has an extra set of contacts and use that to illuminate your sign.
     
  7. davenn

    davenn Moderator

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    I do agree with the other guys … you really should know how to do something as easy as this

    BUT in my kindness and as HUGE hint …… google RF sniffer circuits

    you just choose the most suitable one, and modify the one to turn on a lamp,
    Note, if using SSB you may have a pulsing of the light problem and without some
    thought as to the output, you will find the lamp goes off with every breath you take
    NOT an idea situation

    wonder if you understand why ?

    This is where @WHONOES idea is much better

    you haven't said what kind of radio you have or what bands you want this to operate on
    …. this also adds to the problems of the RF sniffer

    and again to use some existing switching from the radio would be better
    there may already be a switched output in the ACC socket on the back of the radio ??


    Dave
     
    Last edited: Sep 7, 2018
  8. Externet

    Externet

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    Not even extra set of contacts is needed. The existing single grounded PTT line can be used for multiple things.
     
  9. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    I was under the impression that there are amateur licences these days that don't require too much technical knowledge.

    I have heard some complain that the requirement is simply enough money to purchase equipment.

    As a "not an amateur radio licence holder", my first thought was a sniffer coil, but my second was that it should simply come on when a transmitter is powered up. Whilst you may not technically be "on the air" until you key the mic, is there anything you don't want people doing in the second after you key the mic that was ok or safe in the second up to it?
     
  10. kellys_eye

    kellys_eye

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    That's too true - and it's not 'don't require too much technical knowledge', it's ZERO technical knowledge - they do, however, insist on 'procedural knowledge' - which is all that black-box users need to know.
     
  11. Alec_t

    Alec_t

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    If your radio is feeding an external antenna efficiently, would there be enough energy 'close' to the radio to be detectable with an RF sniffer?
     
  12. 73's de Edd

    73's de Edd

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    Hey . . . .Mr 'tater man . . . . . . . aka Pierre . . . .

    I would want 2 specific qualifiers . . . . .frequencies of operation and output wattage power level ?
    And MOST important . . .the brand and model of trans/mitter/ceiver .
    (Guess where the 73's de . . . .(with CW code users understanding the de) and a vintage 4 letter call sign come from?)

    ASIDE . . . .
    How cum . . .response #5 PERFECTLY mates up with the user avatar ?


    73's de Edd
    .....
     
    Last edited: Sep 8, 2018
  13. Externet

    Externet

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    Last edited: Sep 8, 2018
    hevans1944 likes this.
  14. Jeanguypataterubberboot

    Jeanguypataterubberboot

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    I really don't know where you get your information. Have you even looked at the Extra class manual? I'm not sure how it is in Scotland but if you think there is zero technical knowledge to pass this you are out of your mind. I hate when people with electronic engineering backgrounds become ham radio operators and think that people who take up the hobby (and that's what this is in case you were unaware, a HOBBY) need to get an electronic engineering degree in order to participate or belittle them just to inflate their own self esteem because they have no life outside of their one passion. I am an airline pilot and have been for 25 years but I don't make statements like "Oh, these guys getting into aviation today don't know jack shit about flying. In order to become a private pilot they need to know everything that an airline rated pilot knows". Old "DINOSAURS" like you are why the hobby is dying. The kids today who ask questions on this forum and get idiotic answers like the one I read at the top of the thread "You have an amateur radio license and still need to ask this question"? are not going to be motivated to continue with the hobby.
     
  15. Jeanguypataterubberboot

    Jeanguypataterubberboot

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    Jul 9, 2013
  16. Jeanguypataterubberboot

    Jeanguypataterubberboot

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    Jul 9, 2013
    I wasn't sure. It's for a 2m fm radio. Signal might be a bit weak which is why I was looking at amplifying it. I wanted something that doesn't have to be physically connected to the coax.
     
  17. Jeanguypataterubberboot

    Jeanguypataterubberboot

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    Jul 9, 2013
    It's an IC-7100 from ICOM on 2m and 70cm. From 5 to 50 watts. I don't expect it to work on SSB due to lack of carrier. It would just maybe flash a bit.

    As for the de in CW. I imagine it's from the french or spanish translation "from". As for 73 I would say it's for brevity. In CW 7 is the opposite of 3. Guessing. I haven't researched it.
     
  18. hevans1944

    hevans1944 Hop - AC8NS

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    Most hams try to avoid "RF in the shack" as part of good amateur radio practice. Am ICOM IC-7100 is an excellent Japanese-manufactured mobile HF, 6m, 2m, and 70cm rig, much favored by appliance operators who just want to get "On the Air" without having to farkle around with their rigs. It's pretty much plug-and-chug leaving only your choice of antenna to complete your "rig". If all you want is something to "sniff" the RF in the near-field of your 2m antenna, a cheap field-strength meter such as the MFJ-801 should be adequate for the job if you locate it near your 2m antenna.

    [​IMG]
    You will have to add the necessary circuits "inside the box" and perhaps run a cable between the meter and the location of your illuminated sign to operate the "ON THE AIR" vanity light, but that should not be a problem.
     
  19. Externet

    Externet

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    :confused:
     
    hevans1944 likes this.
  20. davenn

    davenn Moderator

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    Sep 5, 2009

    and that is why I suggested to you looking at the ACC socket lines …. there's sure to be a TX on line there for switching pre/power amps

    but you didn't bother to respond to that
     
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